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Ionising radiation

Environmental Radioactivity - Medicine - Occupational Radiation Protection - Nuclear Hazards Defence

Ionisierende Strahlung

Tissue Reactions

Deterministic Effects

  • Radiation doses exceeding a threshold of about 500 millisieverts (mSv) can cause tissue reactions (deterministic effects) in the human body.
  • Acute radiation injuries occur within days and weeks after high radiation exposures.
  • Some deterministic effects appear later like pulmonary fibrosis (6 to 24 months after exposure).
  • Radiation below the threshold dose causes no acute effects. For stochastic effects, which are always late effects, no threshold can be specified.

Glossary EntryDeterministic radiation damage

Deterministic radiation damage has a threshold dose value below which the effect does not occur. If the threshold dose is exceeded, the severity of the effect increases with increasing dose. Examples for deterministic effects are skin erythema and epilation.

Glossary EntryStochastic radiation damage

Of a random nature. Radiation effects are referred to as "stochastic" when the probability of a damage resulting from radiation increases with increments of dose, whereas the severity of damage is not affected by the dose. Cancer and leukaemia are examples for stochastic damage.

Radiation doses exceeding a threshold of about 500 millisieverts (mSv) can cause tissue reactions in the human body, also called deterministic effects. They are the result of a massive cell killing and the subsequent loss of function of the affected organs or tissues. Particularly

  • the skin,
  • the hair, and
  • the gastrointestinal epithelium

are affected. Above the dose-threshold, the severity of the injury increases with dose and the damage appears earlier after higher doses.

Acute radiation injuries

Acute radiation injuries are counted among deterministic radiation effects or tissue reactions. They occur shortly (within days and weeks) after high radiation exposures, for example after a nuclear accident. Acute radiation effects comprise among others:

  • erythema (skin redness),
  • hair loss,
  • fertility impairment, and
  • anemia.

Radiation below the threshold dose causes no acute effects. For stochastic effects, which are always late effects, no threshold can be specified.

Radiation protection defines dose limits that rule out acute radiation injuries.

Late deterministic effects

Usually, deterministic effects are acute effects. Still, there are some late deterministic effects like pulmonary fibrosis (increase in fibrous connective tissue leading to loss of pulmonary function). It appears 6 to 24 months after exposure.

State of 2017.01.30

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